On break of stone:
 Loop all entities in radius 2 of event-block:
  If loop-entity is not alive:
   Remove loop-entity
   Add 1 to {cb::%player%}
On pickup of cobble stone:
 If {cb::%player%} is bigger than 0:
  Remove 1 cobble stone from player
  Remove 1 from {cb::%player%}